Apparatus for slag removal



Dec. 26, 1967 KARL-HEINZ HELLMUND APPARATUS FOR SLAG REMOVAL Filed Sept. 9, 1965 INVENTOR. a rL- He r HeLLmund /WR/VEY United States Patent O 7 Claims. ci. zaa-34 Iron tools for poking and removing slag in industrial furnaces used 'for' metallurgcal purposes where very high temperatures and large amounts of heat occur, are subjected to very considerable wear due to oxidation and deformation. Thus for instance the life of slag scrapers in open-hearth and electric furnaces is so limited, that for a single charge several may be required and this is a considerable cost factor.

In order to prolong their service life, it is known to use scrapers having a hollow shaft through which a liquid cooling medium, for example Water, fiows in a closed circuit. The return flow of the heated cooling medium occurs through a pipe which begins at the extreme outer end of the scraper and is arranged inside the scraper and shaft in such a manner that inside the shaft it is flushed on all sides by fresh cooling medium, so that the shaft does not become too warm and can be held with bare hands.

The known types of devices can, however, only be used for smelting furnaces with a lateral pouring spout. They cannot be used in induction type crucible furnaces where the crucible opening is at the top of the furnace. The object of the invention is to avoid this disadvantage. It concerns a method for removing the slag from the melt in crucible smelting furnaces. In accordance with the invention the slag is pushed together, lifted, and removed by means of two slag shovels which can dip into the slag, be mechanically lifted and lowered, and also swivelled in one plane.

The foregoing objects and advantages of the invention will become more apparent from the following detailed description of one ernbodiment thereof, and from the accompanying drawing, wherein:

FIGURE l is a view in side elevation of the improved apparatus for removing slag from a crucible-type smelting furnace; and

FIGURES 2 and 3 are generally plan views looking down upon the interior of the crucible and showing the slag shovels 3 in two different positions, the two shovels being open in FIGURE 2 and brought together in FIG- URE 3.

With reference now to the drawings, and particularly to FIGURE 1, the device for removing slag from liquid metal 1 which fills a crucible 2 is arranged above the surface of the liquid metal and is seen to be comprised of two slag shovels 3, each of which is connected to a vertical Operating shaft 4. The two shafts 4 are arranged parallel to each Other a short distance apa't. At the end furthest away from the furnace crucible, they can each be provided with a gear wheel 6, the gear wheels 6 being in engagement with each other. The Operating shafts can be actuated by a gear 7 which on the one hand is in direct connection with one of the Operating shafts 4 and on the other hand with a drive not shown in the drawing. The bearing of the Operating shafts 4 can be connected to the supporting arm 8 of a hoisting device for raising and lowering. This device can consist of a hollow column 9 on which the supporting arm 8 is mounted in a slidable manner. The column 9 together with a lifting device 10, by means of which the supporting arm can be raised and lowered, can be fixed to a platform 11 which rests on a 3,360,254 Patented Dec. 26, 1967 foundation 13 by way of ball bearings 12 so that it can be swivelled.

A swivel mechansm can also be provided which consists of a driving disc 14 connected to the platform 11, a driving belt or chain 15, and a gear 16, as well as a driving motor 17. The bearing 5 of the Operating shafts 4 can on account of the high Operating temperatures be cooled down to the slag shovels with gas, particularly air. The cooling gas is supplied to bearing 5 through the hollow column 9 by way of a hose 18 through the supporting arm 8.

FIGS. 2 and 3 show a plan view looking down on the crucible 2 with the slag shovels 3 in the operational position. When the slag shovels are dipped into the slag on the melt, they are in the position shown in FIG. 2. As soon as the slag shovels have been dipped far enough into the slag, the required depth being adjusted by means of the hoisting device 10, the slag shovels 3 are swivelled by the Operating shafts 4. The slag is thus pushed together by the slag shovels 3. When the shovels have reached the position shown in FIG. 3, the supporting arm 8 together with the shovels 3 can be raised by the lifting device 10 until the shovels 3 and the slag which is enclosed by them are above the crucible. The supporting arm 8 is then caused to swivel by means of the swivel mechansm until the blades 3 filled with slag have reached a position where the slag can be removed.

The invention is not restricted to this constructional form. Thus for instance it may be expedient to provide platform 11 Whith wheels. It is also an advantage if the slag shovels 3 are made of metal, ceramic material, graphite, Wood, or a combination of two or more of these or similar materials.

I claim:

1. Apparatus for removing slag from the melt in a smelting furnace of an open top crucible type which comprises a pair of vertically disposed parallel Operating shafts arranged for rotation about their axes, a shovel secured in a generally horizontal attitude at the lower end of each said shaft, whereby to enable the slag engaging edges of said shovels to be brought together or separated dependent upon the rotational direction of their respective Operating shafts, means for lowering and raising said shafts and shovels Secured thereto into and out of the mouth of said crucible for lateral scooping up and removal of the slag on the melt, and means for moving said shafts and shovels laterally of the crucible mouth when in a raised position.

2. Apparatus as defined in claim 1 for removing slag from the melt in a smelting furnace of the crucible type wherein said means for moving said shafts and shovels laterally of the crucible mouth is constituted by a horizontally positioned supporting arm on which said operating shafts and shovels are mounted, and pivotal support` ing means for said arm to permit swinging movement thereof and of said Operating shafts and shovels over the mouth of said crucible.

3. Apparatus as defined in claim 2 for removing slag from the melt in a smelting furnace of the crucible type and which further includes means for raising and lowering said supporting arm thereby to raise and lower said Operating shafts and shovels.

4. Apparatus as defined in claim 1 for removing slag from the melt in a smelting furnace of the crucible type which further includes bearings for said Operating shafts and means for passing a fluid coolant in heat excrange relation with said bearings for cooling the same.

5. Apparatus as defined in claim 1 for removing slag from the melt in a smelting furnace of the crucible type wherein said Operating shafts are provided with meshed gearing for rotational operation in common.

6. Apparatus for removing slag from the melt in a smeltirg furnace of the open top crucible type which comprises a platform located adjacent the crucible, a column upstanding on said platform and which is rotatable about its aXis, a support arm extending horizontally outward from said column, a pair of vertically disposed Operating shafts depending from said support arm and mounted for rotaton about their axes, a shovel secured in a generally horizontal attitude at the lower end of each said shaft whereby to enable the slag engaging edges of said shovels to be brought together or separated dependent upon the rotational direction of their respective Operating shafts, means for lowering and raising said support arm on said column thereby to lower and raise said Operating shafts and shovels into and out of the mouth of .said crucible, and means for rotating said column and support arm thereon thereby to enable said Operating shafts and shovels when in their raised position to be moved laterally of the mouth of the crucible.

7. Apparatus as defined in claim 6 for removing slag from the melt in a smelting furnace of the open top crucible type which further includes fluid cooled bearings for said shovel Operating shafts, and means delivering a fluid coolant to said bearings which comprises a coolant feed pipe located inside of said column and a flexible hose section extending from the upper end of said feed pipe to said support arm and thcnce to said bearings.

References Cited UNITED STATES PATENTS :263,230 8/1'882 Sargent 87--183 2,195,092 3/1940 Muller et al. 266-34 2,699,933 1/1955 Siefert 266-37 2,854,146 9/1958 Nebolsine et al. 210-525 WILLIAM J. STEPHENSON, Primary Exam'ner.

E. MAR, Assistant Examiner. 

1. APPARATUS FOR REMOVING SLAG FROM THE MELT IN A SMELTING FURNACES OF AN OPEN TOP CRUCIBLE TYPE WHICH COMPRISES A PAIR OF VERTICALLY DISPOSED PARALLEL OPERATING SHAFTS ARRANGED FOR ROTATION ABOUT THEIR AXES, A SHOVEL SECURED IN A GENERALLY HORIZONTAL ATTITUDE AT THE LOWER END OF EACH SAID SHAFT, WHEREBY TO ENABLE THE SLAG ENGAGING EDGES OF SAID SHOVELS TO BE BROUGHT TOGETHER OR SEPARATED DEPENDENT UPON THE ROTATIONAL DIRECTION OF THEIR RESPECTIVE OPERATING SHAFTS, MEANS FOR LOWERING AND RAISING SAID SHAFTS AND SHOVELS SECURED THERETO INTO AND OUT OF THE MOUTH OF SAID CRUCIBLE FOR LATERAL SCOOPING UP AND RE- 